Forced disruption of the ovarian function of animals such as cows or pigs is known to suppress the estrus cycle of the females, bringing about an improvement in their growth rate and appetite and thus increasing meat production.
For ovarian dysfunction, ovariectomy is conventionally performed on female animals. In this case, the operation scar resulting from an abdominal incision degrades the commercial value and quality of meat of the female animals. Also, ovariectomized animals are difficult to manage in terms of postoperative rehabilitation for the prevention of inflammation of incision sites. Further, an ovariectomy cost, which is generally high, is negatively influential in terms of the economy of meat production.
Alternatively, a progesterone-based agent for inhibiting ovulation and follicular maturation may be fed, together with fodder, to animals to inhibit ovarian function. However, this strategy is imparted with a continuous burden of drug expense, and thus is economically ineffective. Also, the feeding of such hormone inhibitors results in the presence of hormonal ingredients, so that the meat product cannot be given hormone-free certification.
The equipment disclosed in Korean Patent Application Unexamined Publication No. 10-2007-0041658 (entitled “Equipment of myolysis using laser”, hereinafter referred to as “Reference 1”), may be utilized to stop ovarian function, without an abdominal incision. In this regard, the sharp-pointed tip of the equipment may be allowed to penetrate into the functional tissue of the ovary, with the subsequent introduction of a drug, instead of laser, to the ovary. However, this method is cumbersome because it requires an ultrasonic machine and a camera for securing a view for operation, as well as an ingress guiding instrument. Further, the method is burdened with a cost of performing various processes with the instrument, causing an increase in the production cost of meat. Consequently, Reference 1 is difficult to apply in practice.
In order to overcome these disadvantages, the present inventor suggested a device as disclosed in Korean Patent No. 10-1254705 (entitled “Medicine injection device for animal ovary deactivation”, hereinafter referred to as “Reference 2”).
As shown in FIG. 1, the device comprises a catheter to a front portion of which a stopper is fixedly coupled and to a rear portion of which a needle-equipped communication tube is inserted, with a piston placed within the communication tube. The communication tube is also provided with a stopping ring at a rear side thereof, and a stopper is provided at a rear side of the catheter. The piston within the communication tube is connected with a thumb rest through a connection rod.
Having the aforementioned structure, the device of Reference 2 can allow the needle to safely reach a functional ovarian tissue, and thus functions as a device by which a drug for introducing ovarian dysfunction can be conveniently and economically injected. The device of Reference 2 is structured such that the needle is confined within the catheter until the catheter precisely reaches the functional tissue of the ovary. When reaching the functional tissue, the needle is extended from the catheter and penetrates into the functional ovarian tissue by a simple operation. In this position, the drug for introducing ovarian dysfunction is injected by pressing the thumb rest. Subsequently, the needle is retracted and the catheter is entirely withdrawn to finish the operation conveniently and economically.
Thus, Reference 2 can suppress the estrus of female animals, with the consequent advantages of improving growth rate and appetite, increasing meat productivity, avoiding post-operative problems, such as degradation of quality of meat resulting from abdominal incision, a burden of high operative cost and post-operative care, etc., and overcoming the problems encountered with the long-term administration of ovulation and follicular maturation inhibitors in terms of cost and hormone-free certification.
Since not necessitating various instruments including ultrasonic devices, Reference 2 can prevent an increase in the production cost of meat in addition to helping the operation be safe and simple.
Accordingly, a composition for inducing ovarian dysfunction that is applicable to the device of Reference 2 is required. So far, no ovarian dysfunction-inducing compositions that guarantee the safety of meats as foods and which prevent the degradation of quality of meats have been known. There is therefore a need for a composition for inducing ovarian dysfunction that is applicable to the device of Reference 2 and which allows the meat to be produced with high quality and which is safe for ingestion.